The mother of one of the named students said the incident started Tuesday afternoon during a classroom journal writing exercise. One of the girls wrote and read aloud the names of students she wanted to kill, though not within earshot of the teacher.

"My daughter said to her, 'You want to kill me?'" said the mother, who did not want her name used. "She said, 'Yes I want to kill you.'"

The mother said her daughter called her from a school bathroom, terrified and in tears.

The school's principal told the mother that the girl who made the threats would be pulled from school and not allowed to return until she was evaluated by a doctor. But the girl was back in school the next day, in a different classroom, because she'd gotten medical clearance.

That afternoon, another student in the class found the threatening video on YouTube. Along with the girl who named classmates, another student participated off-camera.

"She got into detail, that she's going to stab, kill, choke," said the mother. "You can't finish the video, you're so shocked this girl's actually talking this way."

A spokesperson for Paterson schools said the two students have been "removed from the school environment," though it wasn't clear whether they were officially suspended.

"We have been communicating with the parents who had children in the same class as these two students," said Terry Corallo. "We have assured these parents that we have taken this issue very seriously and are taking the necessary steps to address this issue.

"Additionally, the video has been pulled from YouTube. This is now a police investigation and they will have our full cooperation."

The mother of the threatened girl, along with other parents, told NBC 4 New York administrators only removed the girls from class after they reached out to police and to the prosecutor's office.

They said they've learned the two girls have been charged and will be in court Monday, though neither school officials nor Paterson Police have confirmed that.

No one answered the door at the homes of the two girls Thursday evening.